1. Field of the Invention
The invention relates generally to the field of electronic packaging. More particularly, the present invention relates in one embodiment to a diversity antenna incorporated as part of an electronic package for a wireless location and tracking system and/or wireless communication system (WCS).
2. Description of Related Technology
In conventional electronic packaging, a device (e.g., a printed circuit board, digital, analog, RF, or microwave integrated circuit) may be mounted into a cavity of a metal or plastic package. A lid placed over the package partially shields the device from its environment. Electrical connectors or adapters (such as coax, SMA, twin-lead, wiring-harness, RF or DC pad, RF or DC feed-through) connect components on the device to one or more external devices such as power supplies, networks and communication systems. These conventional electronic packaging processes have potentially disadvantages including high assembly costs, questionable durability (such as mechanical resistance to shock and vibration), as well as long lead time machine tooling.
Conventional circuit encapsulation methods include mounting a printed circuit board (PCB) or integrated circuit (to produce an RFID—Radio Frequency Identification Device) within one or more multi-layer plastic sheets. Other conventional electronic packaging methods include encasing a transponder in a sealed member, overmolding devices having a ferrite, powdered metal and magnet core materials and associated circuitry, integrally molding an RFID tag “in situ” within a plastic body or forming a series of injection-molded segments containing separate electrical or mechanical components. Accordingly, various prior art patents disclose plastic, ceramic, and metallic packages for transponders and RFID devices (e.g., US Published Patent Applications 20020180602, 20020196123, 20050248459, 20060290497, and issued U.S. Pat. Nos. 5,967,841, 5,973,599, 6,882,897, 5,785,181 which are herein incorporated by reference).
One important property for an electronic tracking device is durability. For instance, children, Alzheimer's syndrome patients or mentally ill persons, carrying an electronic tracking device may cause the device to strike a hard or sharp surface. Wild animals tagged with an electronic tracking device may expose the device to water when exiting or entering a lake, stream, or snowfall. In addition, continued monitoring of a discarded electronic device under harsh environmental conditions (e.g., when placed in a trash receptacle) may assist locating a lost or abducted individual.
Other important properties of an electronic tracking device include receiver sensitivity as well as antenna directivity. For instance, a GPS satellite, GPS repeater station, or RF base station needs to maintain communication with an electronic tracking device. For many conventional electronic tracking devices, internal antennas may be generally categorized into patch and quadrifilar helix antennas. In one conventional system, a patch antenna and a low noise amplifier mounted along a horizontal plane of an electronic tracking device provides antenna directivity in accordance with a hemispherical response but provides poor receiver sensitivity when the device is positioned on its edge (e.g., aligned along a vertical plane in an individual's shirt pocket). In another conventional system, a quadrifilar helical antenna mounted along a vertical plane of the electronic tracking device occupies a large restate area; thus, miniaturization of an electronic package size is compromised. Furthermore, a quadrifilar helical antenna mounted along a vertical plane provides poor receiver sensitivity when the electronic tracking device is not aligned in a skyward fashion.
Other important properties of an electronic tracking device include an ability to replenish its battery level and as well as provide a means of efficient data transfer, e.g., when a device battery is charging and may be electrically connected to a remote terminal, e.g., a location coordinate monitoring station. Many conventional electronic tracking devices power replenish and recharge capability is limited to physically plugging a port of the electronic tracking device into a standard electrical wall outlet or, in yet another instance, physical replacement of a device battery. Furthermore, many conventional electronic tracking devices provide signal transfer capability limited to direct connection of the electronic tracking device to a sub-station or central location coordinate monitoring station.
In summary, a novel electronic tracking device package is needed to produce a durable device that provides enhanced electrical properties, e.g., improved receiver sensitivity, and antenna directivity, and other advantages in one or more embodiments such as one or more battery level charging options, remote signal processing, data and software update options, and a deterrent to reverse engineering schematics and hardware configurations of the electronic tracking device.